A power amplifier is used to amplify radio frequency signals to be transmitted from an antenna of a wireless device such as a mobile telephone. A number of conventional power amplifiers employ bias circuitry that provides an inadequate bias signal level when the radio frequency signals reach a peak power level. As such, these conventional power amplifiers often suffer from output signal distortion at peak power levels. For example, the inadequate bias signal level results in amplitude modulation-amplitude modulation distortion that can cause an out-of-specification adjacent channel leakage ratio. Thus, a power amplifier system having a bias circuitry that provides adequate bias signal levels at all power levels is needed.